Analysis of liver metastasis after resection for pancreatic ductal adenocarcinoma

Clinical Relevance of Cancerization of Ducts in Resected Pancreatic Ductal Adenocarcinoma

OBJECTIVES

Although prevalent in 50%-90% of pancreatic ductal adenocarcinomas, the clinical relevance of "cancerization of ducts" (COD) remains unknown.

METHODS

Pathologists retrospectively reviewed slides classifying prevalence of COD. Histopathological parameters, location of first recurrence, recurrence-free survival (RFS), and overall survival (OS) were collected from the institutional pancreatectomy registry.

RESULTS

Among 311 pancreatic ductal adenocarcinomas, COD was present in 216 (69.5%) and more prevalent in the cohort that underwent upfront surgery (75.3% vs 63.1%, P = 0.019). Furthermore, COD was associated with female gender (P = 0.040), advanced T stage (P = 0.007), perineural invasion (P = 0.014), lymphovascular invasion (P = 0.025), and R1 margin (P = 0.009), but not N stage (P = 0.401) or tumor differentiation (P = 0.717). In multivariable regression, COD was associated with less liver recurrence (odds ratio, 0.44; P < 0.005). This association was driven by the cohort of patients who had received preoperative treatment (odds ratio, 0.18; P < 0.001). COD was not predictive for RFS or OS.

CONCLUSIONS

Cancerization of ducts was not associated with RFS or OS. Currently underrecognized, standardized implementation into histopathological reports may have merit, and further mechanistic scientific experiments need to illuminate its clinical and biologic impact.

A Liver-First Approach Using Ablation for Oligometastatic Pancreatic Cancer: A Report of a Successful Case

Pancreatic cancer (PC) is a highly aggressive malignancy, often accompanied by liver metastases as a common manifestation. While palliative chemotherapy remains the mainstay treatment for liver metastatic PC, local treatment approaches have gained attention, especially for patients with oligometastasis who exhibit a positive response to chemotherapy. This case report illustrates the successful application of a liver-first strategy in a 79-year-old male diagnosed with liver oligometastatic PC, originating in the pancreatic tail. The strategy encompassed percutaneous microwave ablation for liver metastases, followed by FOLFIRINOX (5-fluorouracil, folic acid, irinotecan, and oxaliplatin) chemotherapy, and subsequent primary tumor resection. The patient has remained disease-free for over a year post-surgery. This multidisciplinary approach may hold promise for selected patients with liver oligometastatic PC, although further research and case studies are needed for comprehensive evaluation.

Identification of Genes Associated with Liver Metastasis in Pancreatic Cancer Reveals PCSK6 as a Crucial Mediator

Liver metastasis occurs frequently in patients with pancreatic cancer. We analyzed the molecular profiling in liver metastatic lesions aiming to uncover novel genes responsible for tumor progression. Bioinformatics analysis was applied to identify genes directing liver metastasis. CRISPR/Cas9 technology was used to knock out the candidate gene. Proliferation assays, colony formation assays, cell cycle analysis, migration assays, wound healing assays, Immunofluorescence analysis, and the tumor xenograft model of intrasplenic injection were adopted to evaluate the effects of PCSK6 inactivation on cell growth, migration and liver metastasis. GSEA and Western blot were used to investigate the corresponding signaling pathway. PCSK6 was one of the obtained liver-metastasis-related genes in pancreatic cancer. PCSK6 inactivation inhibited cell growth and cell migration, due to G0/G1 cell cycle arrest and the remodeling of cell-cell junctions or the cell skeleton, respectively. PCSK6 inactivation led to fewer counts and lower outgrowth rates of liver metastatic niches in vivo. The Raf-MEK1/2-ERK1/2 axis was repressed by PCSK6 inactivation. Accordingly, we found PCSK6 inactivation could inhibit cell growth, cell migration, and liver metastasis, and explored the role of the Raf-MEK1/2-ERK1/2 axis in PCSK6 inactivation. PCSK6-targeted therapy might represent a novel approach for combatting liver metastasis in pancreatic cancer.

Recurrence After Resection of Pancreatic Cancer: Can Radiomics Predict Patients at Greatest Risk of Liver Metastasis?

BACKGROUND

Liver metastasis (LM) after pancreatic ductal adenocarcinoma (PDAC) resection is common but difficult to predict and has grave prognosis. We combined preoperative clinicopathological variables and quantitative analysis of computed tomography (CT) imaging to predict early LM.

METHODS

We retrospectively evaluated patients with PDAC submitted to resection between 2005 and 2014 and identified clinicopathological variables associated with early LM. We performed liver radiomic analysis on preoperative contrast-enhanced CT scans and developed a logistic regression classifier to predict early LM (< 6 months).

RESULTS

In 688 resected PDAC patients, there were 516 recurrences (75%). The cumulative incidence of LM at 5 years was 41%, and patients who developed LM first (n = 194) had the lowest 1-year overall survival (OS) (34%), compared with 322 patients who developed extrahepatic recurrence first (61%). Independent predictors of time to LM included poor tumor differentiation (hazard ratio (HR) = 2.30; P < 0.001), large tumor size (HR = 1.17 per 2-cm increase; P = 0.048), lymphovascular invasion (HR = 1.50; P = 0.015), and liver Fibrosis-4 score (HR = 0.89 per 1-unit increase; P = 0.029) on multivariate analysis. A model using radiomic variables that reflect hepatic parenchymal heterogeneity identified patients at risk for early LM with an area under the receiver operating characteristic curve (AUC) of 0.71; the performance of the model was improved by incorporating preoperative clinicopathological variables (tumor size and differentiation status; AUC = 0.74, negative predictive value (NPV) = 0.86).

CONCLUSIONS

We confirm the adverse survival impact of early LM after resection of PDAC. We further show that a model using radiomic data from preoperative imaging combined with tumor-related variables has great potential for identifying patients at high risk for LM and may help guide treatment selection.

The identification of liver metastasis- and prognosis-associated genes in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is an often fatal malignancy with an extremely low survival rate. Liver metastasis, which causes high mortality, is the most common recurring metastasis for PDAC. However, the mechanisms underlying this liver metastasis and associated candidate biomarkers are unknown.

METHODS

We performed mRNA profiling comparisons in 8 primary tumors (T) and 12 liver metastases (M) samples using the Gene Expression Omnibus (GEO) database. After determining differentially expressed genes (DEG), gene ontology (GO), pathway enrichment and protein-protein interaction (PPI) network analyses were performed to determine DEG functions. Then, Cytoscape was used to screen out significant hub genes, after which their clinical relevance was investigated using The Cancer Genome Atlas (TCGA) resources. Furthermore, prognosis-associated gene expression was validated using Oncomine and TCGA database. Lastly, associations between prognosis-associated genes, immune cells and immunological checkpoint genes were evaluated using the Tumor Immune Estimation Resource (TIMER).

RESULTS

In total, 102 genes were related to liver metastasis and predominantly involved in cell migration, motility, and adhesion. Using Cytoscape, this number was narrowed down to 16 hub genes. Elevated mRNA expression levels for two of these genes, SPARC (P = 0.019) and TPM1 (P = 0.037) were significantly correlated with poor disease prognosis. For the remaining 14, expression was not related to overall patient survival. SPARC had higher expression in patients with metastatic PDAC than those with non-metastatic PDAC in TCGA dataset. SPARC and TPM1 levels were also positively correlated with the immune infiltration of specific cell types. Additionally, both genes exhibited strong co-expression associations with immune checkpoint genes.

CONCLUSIONS

Combined, we suggest SPARC has high potential as biomarker to predict liver metastasis during PDAC. Additionally, both SPARC and TPM1 appeared to recruit and regulate immune-infiltrating cells during these pathophysiological processes.

A Comparative Study of Survivor Outcomes between Preoperative Evaluation Using CT Alone and Combined CT and MRI in Patients with Pancreatic Ductal Adenocarcinoma

Purpose

Materials and Methods

Results

Conclusion

Diagnostic accuracy of contrast-enhanced diffusion-weighted MRI for liver metastases of pancreatic cancer: towards adequate staging and follow-up of pancreatic cancer - DIA-PANC study: study protocol for an international, multicenter, diagnostic trial

BACKGROUND

At the time of surgery, approximately 10-20% of the patients with pancreatic cancer are considered unresectable because of unexpected liver metastasis, peritoneal carcinomatosis or locally advanced disease. This leads to futile surgical treatment with all the associated morbidity, mortality and costs. More than 50% of all liver metastases develop in the first six months postoperatively. These (subcentimeter) liver metastases are most likely already present at the time of diagnosis and have not been identified pre-operatively, due to the poor sensitivity of routine preoperative contrast-enhanced CT (CECT).

METHODS

The DIA-PANC study is a prospective, international, multicenter, diagnostic cohort study investigating diffusion-weighted, contrast-enhanced MRI for the detection of liver metastases in patients with all stages of pancreatic cancer. Indeterminate or malignant liver lesions on MRI will be further investigated histopathologically. For patients with suspected liver lesions without histopathological proof, follow up imaging with paired CT and MRI at 3-, 6- and 12-months will serve as an alternative reference standard.

DISCUSSION

The DIA-PANC trial is expected to report high-level evidence of the diagnostic accuracy of MRI for the detection of liver metastases, resulting in significant value for clinical decision making, guideline development and improved stratification for treatment strategies and future trials. Furthermore, DIA-PANC will contribute to our knowledge of liver metastases regarding incidence, imaging characteristics, their number and extent, and their change in time with or without treatment. It will enhance the worldwide implementation of MRI and consequently improve personalized treatment of patients with suspected pancreatic ductal adenocarcinoma.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03469726 . Registered on March 19th 2018 - Retrospectively registered.

Recurrence Patterns for Pancreatic Ductal Adenocarcinoma after Upfront Resection Versus Resection Following Neoadjuvant Therapy: A Comprehensive Meta-Analysis

Background: Neoadjuvant therapy (NAT) represents a paradigm shift in the management of patients with pancreatic ductal adenocarcinoma (PDAC) with perceived benefits including a higher R0 rate. However, it is unclear whether NAT affects the sites and patterns of recurrence after surgery. This review seeks to compare sites and patterns of recurrence after resection between patients undergoing upfront surgery (US) or after NAT. Methods: The EMBASE, SCOPUS, PubMed, and Cochrane library databases were systematically searched to identify eligible studies that compare recurrence patterns between patients who had NAT (followed by resection) with those that had US. The primary outcome included site-specific recurrence. Results: 26 articles were identified including 4986 patients who underwent resection. Borderline resectable pancreatic cancer (BRPC, 47% 1074/2264) was the most common, followed by resectable pancreatic cancer (RPC 42%, 949/2264). The weighted overall recurrence rates were lower among the NAT group, 63.4% vs. 74% (US) (OR 0.67 (CI 0.52–0.87), p = 0.006). The overall weighted locoregional recurrence rate was lower amongst patients who received NAT when compared to US (12% vs. 27% OR 0.39 (CI 0.22–0.70), p = 0.004). In BRPC, locoregional recurrence rates improved with NAT (NAT 25.8% US 37.7% OR 0.62 (CI 0.44–0.87), p = 0.007). NAT was associated with a lower weighted liver recurrence rate (NAT 19.4% US 30.1% OR 0.55 (CI 0.34–0.89), p = 0.023). Lung and peritoneal recurrence rates did not differ between NAT and US cohorts (p = 0.705 and p = 0.549 respectively). NAT was associated with a significantly longer weighted mean time to first recurrence 18.8 months compared to US (15.7 months) (OR 0.18 (CI 0.05–0.32), p = 0.015). Conclusion: NAT was associated with lower overall recurrence rate and improved locoregional disease control particularly for those with BRPC. Although the burden of liver metastases was less, there was no overall effect upon distant metastatic disease.

Integrating Osteopathic Philosophy in Cancer Care

Recent breakthroughs in the fields of genomics and biology have resulted in a better understanding of diseases and their underlying biology. New targeted and immune-based therapies take advantage of these new discoveries to treat the patient individually. This scientific revolution toward personalized medicine reflects osteopathic medicine's emphasis on patient-centered care and its tenets, which go against the "one-size-fits-all" approach. The authors discuss the importance of applying osteopathic philosophy to the delivery of patient-directed cancer care revolutionized by scientific advances.

Evaluation of preoperative prognostic factors in patients with resectable invasive intraductal papillary mucinous carcinoma

BACKGROUND

Upfront surgery is the standard treatment for resectable invasive intraductal papillary mucinous carcinoma; however, recurrence is common. Therefore, we investigated the recurrence, surgical outcome, and preoperative prognostic factors for recurrence in patients with resectable invasive intraductal papillary mucinous carcinoma.

METHODS

We analyzed 111 patients who underwent upfront surgery for resectable invasive intraductal papillary mucinous carcinoma between 2000 and 2017 and evaluated the relationship among clinicopathologic factors, recurrence, and outcomes.

RESULTS

The 5-year recurrence-free survival and disease-specific survival rates were 61% and 74%, respectively. The median time to recurrence was 1.1 years. In multivariate analysis, carbohydrate antigen 19-9 ≥83 U/mL (hazard ratio: 2.8 and 3.1), tumor size ≥2.2 cm (hazard ratio: 3.5 and 4.7), and pathologic tubular adenocarcinoma grade 2 (hazard ratio: 3.1 and 5.2) were risk factors for a shorter recurrence-free survival and disease-specific survival, respectively. Lymph node metastasis (hazard ratio: 3.9) was also a risk factor for a shorter disease-specific survival. When examining outcomes according to preoperatively measurable factors (carbohydrate antigen 19-9 ≥83 U/mL and tumor size ≥2.2 cm), the 5-year recurrence rates in patients with none (n = 47), 1 (n = 46), and both (n = 18) risk factors were 17%, 48%, and 78%, respectively. Five-year disease-specific survival rates in patients with none, 1, and both preoperative risk factors were 95%, 69%, and 31%, respectively.

CONCLUSION

Carbohydrate antigen 19-9 ≥83 U/mL and tumor size ≥2.2 cm were independent preoperative risk factors for poor outcomes in patients with resectable invasive intraductal papillary mucinous carcinoma.

Comparison of patients with invasive intraductal papillary mucinous carcinoma and invasive ductal carcinoma of the pancreas: a pathological type- and stage-matched analysis

Objective: We compared the pathological features and stage-matched outcomes of patients with invasive intraductal papillary mucinous carcinoma (IPMC) and invasive ductal carcinoma (IDC) of the pancreas to identify the reasons for these diseases' differing prognoses.Methods: We analyzed 114 and 560 patients who underwent curative pancreatectomy for invasive IPMC and IDC, respectively, and analyzed their clinicopathological factors.Results: The disease-specific survival (DSS) of patients with invasive IPMC was significantly superior to that of patients with IDC exhibiting all pathological types at all stages. The DSS of patients with invasive IPMC exhibiting tubular adenocarcinoma was significantly superior to that of their counterparts with IDC only among those with stage IIB (p = .045). When comparing patients with stage IIB tubular adenocarcinoma-type invasive IPMC to their counterparts with IDC, the tumor size (2.6 cm vs. 3.3 cm, p = .010), serum level of carbohydrate antigen 19-9 (253 vs. 474 U/mL, p = .035), number of metastatic lymph nodes (3.1 vs. 4.5, p = .033), vascular invasion rate (14% vs. 41%, p = .0019) and local invasion rate (79% vs. 95%, p = .0045) were lower in the former group. Moreover, the frequency of pathological tubular adenocarcinoma grade 1 was higher in patients with invasive IPMC than in those with IDC (38% vs. 12%, p = .0004) as was the R0 resection rate (90% vs. 65%, p = .0027).Conclusions: In pathological type- and stage-matched analyses, invasive IPMC was associated with a better prognosis than IDC only in patients with stage IIB, as factors governing tumor aggressiveness were milder in the former group than in the latter.

Macrophage-derived exosomal microRNA-501-3p promotes progression of pancreatic ductal adenocarcinoma through the TGFBR3-mediated TGF-β signaling pathway

Background

Exosomes from cancer cells or immune cells, carrying bio-macromolecules or microRNAs (miRNAs), participate in tumor pathogenesis and progression by modulating microenvironment. Our study aims to investigate the role of these microRNA-501-3p (miR-501-3p) containing exosomes derived from tumor-associated macrophage (TAM) in the progression of pancreatic ductal adenocarcinoma (PDAC).

Methods

Firstly, the function of TAM recruitment in PDAC tissues was assessed, followed by identification of the effects of M2 macrophage-derived exosomes on PDAC cell activities and tumor formation and metastasis in mice. In silico analysis was conducted to predict differentially expressed genes and regulatory miRNAs related to PDAC treated with macrophages, which determined miR-501-3p and TGFBR3 for subsequent experiments. Next, gain- and loss-of-function experiments were performed to examine their role in PDAC progression with the involvement of the TGF-β signaling pathway.

Results

TAM recruitment in PDAC tissues was associated with metastasis. Highly expressed miR-501-3p was observed in PDAC tissues and TAM-derived exosomes. Both M2 macrophage-derived exosomes and miR-501-3p promoted PDAC cell migration and invasion, as well as tumor formation and metastasis in nude mice. MiR-501-3p was verified to target TGFBR3. PDAC cells presented with down-regulated TGFBR3, which was further decreased in response to M2 macrophage treatment. TGF-β signaling pathway activation was implicated in the promotion of miR-501-3p in PDAC development. The suppression of macrophage-derived exosomal miR-501-3p resulted in the inhibition of tumor formation and metastasis in vivo.

Conclusion

M2 macrophage-derived exosomal miR-501-3p inhibits tumor suppressor TGFBR3 gene and facilitates the development of PDAC by activating the TGF-β signaling pathway, which provides novel targets for the molecular treatment of PDAC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1313-x) contains supplementary material, which is available to authorized users.

Evaluation of preoperative prognostic factors in patients with resectable pancreatic ductal adenocarcinoma

Objective: Upfront surgery is the standard treatment for resectable pancreatic ductal adenocarcinomas (R-PDACs); however, these tumors often recur. We investigated the factors governing recurrence and prognosis in patients with R-PDAC. Methods: We analyzed 359 patients who underwent upfront surgery for R-PDAC between 2000 and 2016, and evaluated the relationship between clinicopathological factors and recurrence/outcomes. Results: The rate of recurrence was 74% while the median time to recurrence was 1.2 years. On multivariate analysis, carbohydrate antigen 19-9 (CA19-9) >37 U/mL (hazard ratio [HR]: 2.02), tumor size >2.6 cm (HR: 1.50), pathological grade 3 (HR: 2.58), lymph node metastasis (LNM; HR: 1.65), residual tumor (HR: 1.47) and forgoing adjuvant chemotherapy (HR: 1.31) were risk factors for a shorter recurrence-free survival; the median survival time (MST) was 2.8 years. On multivariate analysis, CA19-9 > 37 U/mL (HR: 1.99), tumor size >2.6 cm (HR: 1.43), pathological grade 3 (HR: 2.93), pathological portal vein invasion (HR: 1.48), LNM (HR: 1.79) and forgoing adjuvant chemotherapy (HR: 1.39) were risk factors for shorter disease-specific survival intervals. When examining outcomes according to preoperatively measurable factors (CA19-9 > 37 U/mL and tumor size >2.6 cm), the median time to recurrence and MSTs of patients with none (n = 83), one (n = 112) and both (n = 164) risk factors were 3.2, 1.8 and 0.8 years; and 7.2, 4.0 and 1.7 years, respectively. Conclusions: CA19-9 > 37 U/mL and tumor size >2.6 cm were preoperative independent risk factors for early recurrence and poor outcomes in patients with R-PDAC. Therefore, preoperative treatment should be considered for such patients.

Safety of Islet Autotransplantation After Pancreatectomy for Adenocarcinoma

BACKGROUND

Total pancreatectomy with intraportal islet autotransplantation (TPIAT) rather than partial pancreatectomy could represent a major shift in the management of patients with resectable pancreatic ductal adenocarcinoma (PDAC) when risks of postoperative pancreatic fistula are well identified. This approach provides a theoretical risk of tumor cell dissemination when islet cells are transplanted into the portal vein. Our objective was to explore the safety of TPIAT in PDAC in a mouse preclinical model of subcutaneous xenotransplantation of human cells isolated from pancreatic specimen during partial pancreatectomy performed for PDAC.

METHODS

Patients requiring pancreatectomy for PDAC were prospectively included. Immunocompromised mice were transplanted with pancreatic cells isolated from the nonmalignant part of the surgical specimen (experimental group). Results were compared with pancreatic tumor implants (control group). Pancreatic grafts were explanted at 6 weeks for histological analyses.

RESULTS

Nine patients were included, and 31 mice were transplanted. In the experimental group, explants were microscopically devoid of tumor cell, and no metastasis was observed. In the control group, all explants were composed of tumor.

CONCLUSIONS

We report in a preclinical model the absence of local and distant spreading of malignant cells after pancreatic islets xenograft isolated from PDAC patients. These data supports the oncological safety of TPIAT as valuable alternative to partial pancreatectomy for PDAC patients with a high risk of postoperative pancreatic fistula.

Instantaneous mutation rate in cancer initiation and progression

BACKGROUND

Cancer is one of the leading causes for the morbidity and mortality worldwide. Although substantial studies have been conducted theoretically and experimentally in recent years, it is still a challenge to explore the mechanisms of cancer initiation and progression. The investigation for these problems is very important for the diagnosis of cancer diseases and development of treatment schemes.

RESULTS

To accurately describe the process of cancer initiation, we propose a new concept of gene initial mutation rate based on our recently designed mathematical model using the non-constant mutation rate. Unlike the widely-used average gene mutation rate that depends on the number of mutations, the gene initial mutation rate can be used to describe the initiation process of a single patient. In addition, we propose the instantaneous tumour doubling time that is a continuous function of time based on the non-constant mutation rate. Our proposed concepts are supported by the clinic data of seven patients with advanced pancreatic cancer. The regression results suggest that, compared with the average mutation rate, the estimated initial mutation rate has a larger value of correlation coefficient with the patient survival time. We also provide the estimated tumour size of these seven patients over time.

CONCLUSIONS

The proposed concepts can be used to describe the cancer initiation and progression for different patients more accurately. Since a quantitative understanding of cancer progression is important for clinical treatment, our proposed model and calculated results may provide insights into the development of treatment schemes and also have other clinic implications.

Preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after curative intent surgical resection

BACKGROUND

Postoperative early recurrence (ER) in patients with pancreatic ductal adenocarcinoma (PDAC) is frequently encountered after curative intent surgery. Nonetheless, clinical significance and risk factors of ER after surgery for PDAC have not been extensively investigated. The aim of this study was to determine preoperative risk predictors for ER in patients with PDAC after upfront surgery.

METHODS

Eighty-one consecutive patients with PDAC who underwent curative intent surgical resection at Kangbuk Samsung Hospital between January 2004 and May 2015 were enrolled. ER was defined as tumor relapse within 6 months after surgery.

RESULTS

ER occurred in 26 patients (32.1%), whereas 49 patients (60.5%) had late recurrence (≥ 6 months after surgery), and 6 patients had no recurrence (7.4%). Univariate analysis showed that C-reactive protein (CRP) > 3.0 mg/dL, modified Glasgow prognostic score (mGPS) = 2, decrease of total lymphocyte count by > 50% of baseline value in the preoperative period, prognostic nutritional index (PNI) < 45, neutrophil-to-lymphocyte ratio (NLR) ≥ 3, and preoperative maximum standardized uptake value (SUVmax) were significantly associated with ER. Multivariate logistic regression analysis revealed that CRP > 3.0 mg/dL, decrease of total lymphocyte count by > 50% of baseline value, and preoperative SUVmax were significant and independent contributors of ER in patients with resectable PDAC who underwent curative intent surgery.

CONCLUSIONS

Postoperative ER for resectable PDAC was frequent with poor prognosis after curative intent upfront surgery. It is reasonable to suggest that there is a subgroup of resectable PDAC patients at high-risk of ER and neoadjuvant therapy should be considered in these patients in a clinical trial setting.

Honokiol suppresses pancreatic tumor growth, metastasis and desmoplasia by interfering with tumor-stromal cross-talk

The poor clinical outcome of pancreatic cancer (PC) is largely attributed to its aggressive nature and refractoriness to currently available therapeutic modalities. We previously reported antitumor efficacy of honokiol (HNK), a phytochemical isolated from various parts of Magnolia plant, against PC cells in short-term in vitro growth assays. Here, we report that HNK reduces plating efficiency and anchorage-independent growth of PC cells and suppresses their migration and invasiveness. Furthermore, significant inhibition of pancreatic tumor growth by HNK is observed in orthotopic mouse model along with complete-blockage of distant metastases. Histological examination suggests reduced desmoplasia in tumors from HNK-treated mice, later confirmed by immunohistochemical analyses of myofibroblast and extracellular matrix marker proteins (α-SMA and collagen I, respectively). At the molecular level, HNK treatment leads to decreased expression of sonic hedgehog (SHH) and CXCR4, two established mediators of bidirectional tumor-stromal cross-talk, both in vitro and in vivo . We also show that the conditioned media (CM) from HNK-treated PC cells have little growth-inducing effect on pancreatic stellate cells (PSCs) that could be regained by the addition of exogenous recombinant SHH. Moreover, pretreatment of CM of vehicle-treated PC cells with SHH-neutralizing antibody abolishes their growth-inducing potential on PSCs. Likewise, HNK-treated PC cells respond poorly to CM from PSCs due to decreased CXCR4 expression. Lastly, we show that the transfection of PC cells with constitutively active IKKβ mutant reverses the suppressive effect of HNK on nuclear factor-kappaB activation and partially restores CXCR4 and SHH expression. Taken together, these findings suggest that HNK interferes with tumor-stromal cross-talk via downregulation of CXCR4 and SHH and decreases pancreatic tumor growth and metastasis.

Laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma: Long-term oncologic outcomes after standard resection

BACKGROUND

Surgical resection is the only curative option in patients with pancreatic ductal adenocarcinoma. Little is known about the oncologic outcomes of laparoscopic distal pancreatectomy. This bi-institutional study aimed to examine the long-term oncologic results of standard laparoscopic distal pancreatectomy in a large cohort of patients with pancreatic ductal adenocarcinoma.

METHODS

From January 2002 to March 2016, 207 patients underwent standard laparoscopic distal pancreatectomy for pancreatic ductal adenocarcinoma at Oslo University Hospital-Rikshospitalet (Oslo, Norway) and Asan Medical Centre (Seoul, Republic of Korea). After the exclusion criteria were applied (distant metastases at operation, conversion to an open operation, loss to follow-up), 186 patients were eligible for the analysis. Perioperative and oncologic variables were analyzed for association with recurrence and survival.

RESULTS

Median overall and recurrence-free survivals were 32 and 16 months, while 5-year overall and recurrence-free survival rates were estimated to be 38.2% and 35.9%, respectively. Ninety-six (52%) patients developed recurrence: 56 (30%) extrapancreatic, 27 (15%) locoregional, and 13 (7%) combined locoregional and extrapancreatic. Thirty-seven (19.9%) patients had early recurrence (within 6 months of operation). In the multivariable analysis, tumor size >3 cm and no adjuvant chemotherapy were associated with early recurrence (P = .017 and P = .015, respectively). The Cox regression model showed that tumor size >3 cm and lymphovascular invasion were independent predictors of decreased recurrence-free and overall survival.

CONCLUSION

Standard laparoscopic distal pancreatectomy is associated with satisfactory long-term oncologic outcomes in patients with pancreatic ductal adenocarcinoma. Several risk factors, such as tumor size >3 cm, no adjuvant chemotherapy, and lymphovascular invasion, are linked to poor prognosis after standard laparoscopic distal pancreatectomy.

An Immunosuppressive Dendritic Cell Subset Accumulates at Secondary Sites and Promotes Metastasis in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) after complete surgical resection is often followed by distant metastatic relapse for reasons that remain unclear. In this study, we investigated how the immune response at secondary sites affects tumor spread in murine models of metastatic PDAC. Early metastases were associated with dense networks of CD11b⁺CD11c⁺MHC-II⁺CD24⁺CD64^lowF4/80^low dendritic cells (DC), which developed from monocytes in response to tumor-released GM-CSF. These cells uniquely expressed MGL2 and PD-L2 in the metastatic microenvironment and preferentially induced the expansion of T regulatory cells (Treg) in vitro and in vivo Targeted depletion of this DC population in Mgl2^DTR hosts activated cytotoxic lymphocytes, reduced Tregs, and inhibited metastasis development. Moreover, blocking PD-L2 selectively activated CD8 T cells at secondary sites and suppressed metastasis, suggesting that the DCs use this particular pathway to inhibit CD8 T-cell-mediated tumor immunity. Phenotypically similar DCs accumulated at primary and secondary sites in other models and in human PDAC. These studies suggest that a discrete DC subset both expands Tregs and suppresses CD8 T cells to establish an immunosuppressive microenvironment conducive to metastasis formation. Therapeutic strategies to block the accumulation and immunosuppressive activity of such cells may help prevent PDAC progression and metastatic relapse after surgical resection. Cancer Res; 77(15); 4158-70. ©2017 AACR.

Multimodality treatment of recurrent pancreatic cancer: Mith or reality?

Pancreatic adenocarcinoma is the fourth cause of cancer-related death in the United States. Surgery is the only potentially curative treatment, but most patients present at diagnosis with unresectable or metastatic disease. Moreover, even with an R0 resection, the majority of patients will die of disease recurrence. Most recurrences occur in the first 2-year after pancreatic resection, and are commonly located in the abdomen, even if distant metastases can occur. Recurrent pancreatic adenocarcinoma remains a significant therapeutic challenge, due to the limited role of surgery and radio-chemotherapy. Surgical management of recurrence is usually unreliable because tumor relapse typically presents as a technically unresectable, or as multifocal disease with an aggressive growth. Therefore, treatment of patients with recurrent pancreatic adenocarcinoma has historically been limited to palliative chemotherapy or supportive care. Only few data are available in the Literature about this issue, even if in recent years more studies have been published to determine whether treatment after recurrence have any effect on patients outcome. Recent therapeutic advances have demonstrated the potential to improve survival in selected patients who had undergone resection for pancreatic cancer. Multimodality management of recurrent pancreatic carcinoma may lead to better survival and quality of life in a small but significant percentage of patients; however, more and larger studies are needed to clarify the role of the different therapeutic options and the optimal way to combine them.

Proposed preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after surgical resection: A multi-center retrospective study

BACKGROUND/OBJECTIVE

Although surgical resection remains the only chance for cure in patients with pancreatic ductal adenocarcinoma (PDAC), postoperative early recurrence (ER) is frequently encountered. The purpose of this study is to determine the preoperative predictive factors for ER after upfront surgical resection.

METHODS

Between 2001 and 2012, 968 patients who underwent upfront surgery with R0 or R1 resection for PDAC at seven high-volume centers in Japan were retrospectively reviewed. ER was defined as relapse within 6 months after surgery. Study analysis stratified by resectable (R) and borderline resectable (BR) PDACs was conducted according to the National Comprehensive Cancer Network guidelines.

RESULTS

ER occurred in 239 patients (25%) with a median survival time (MST) of 8.8 months. Modified Glasgow prognostic score = 2 (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.05-3.95; P = 0.044), preoperative CA19-9 ≥300 U/ml (OR 1.94, 1.29-2.90; P = 0.003), and tumor size ≥30 mm (OR 1.72, 1.16-2.56; P = 0.006), were identified as preoperative independent predictive risk factors for ER in patients with R-PDAC. In the R-PDAC patients, MST was 35.5, 26.3, and 15.9 months in patients with 0, 1 and ≥2 risk factors, respectively. There were significant differences in overall survival between the three groups (P < 0.001). No preoperative risk factors were identified in BR-PDAC patients with a high rate of ER (39%).

CONCLUSIONS

There is a high-risk subset for ER even in patients with R-PDAC and a simple risk scoring system is useful for prediction of ER.

Pancreatic cancer metastasis: are we being pre-EMTed?

Pancreatic cancer, often considered a metastatic disease at the time of clinical diagnosis due to lack of any reliable early diagnostic marker(s), is refractory to conventional chemo- and radiotherapy and has a dismal 5-year survival rate of only 6%. Although surgical removal of the primary tumor is considered to be curative, the 5-year survival rate is no more than 20% even in patients with clear resection margins (R0). The recurrence of local and metastatic disease (primarily liver metastasis) post resection is considered to be the leading cause of mortality in these patients. In addition, instances of metastatic disease without any local recurrence post resection have also been observed. Cancer metastasis is the primary cause of mortality in cancer patients and is classically viewed as a late event during the progression of the disease, which is supported by the genetic studies used to understand the evolution of pancreatic cancer. However, this view has recently been challenged by studies using mathematical modeling and genetically labeled mouse models of pancreatic cancer to understand the dynamics of tumor cell dissemination and epithelial to mesenchymal transition (EMT) of tumor cells well before the primary tumor is formed. Given that EMT is a hallmark process that initiates the metastatic seeding of cancer cells and the dismal prognosis of pancreatic cancer patients even after efficient removal of the primary tumor (99.9%), an early dissemination hypothesis of cancer cells cannot be undermined. In this review, we will discuss the current views regarding pancreatic cancer metastasis with particular emphasis on the epithelial to mesenchymal transition, its influence on the selection of patients for surgical resection and the therapeutic intervention.

Higher overall survival in metastatic pancreatic cancer: the impact of where and how treatment is delivered

Objective

To determine the overall survival of patients with advanced pancreatic cancer and evaluate factors that impact prognosis in a private cancer center.

Methods

Data from the Hospital Cancer Registry at Hospital Israelita Albert Einstein were retrospectively collected. The patients enrolled had metastatic cancer at diagnosis or earlier staging and subsequent recurrence. Cases of neuroendocrine tumors were excluded.

Results

A total of 65 patients were evaluated, including 63 with adenocarcinoma. The median overall survival for patients in all stages was 20.7 months (95%CI: 15.6-25.7), while the overall survival of metastatic disease was 13.3 months. Among the 33 cases with stage IV cancer, there was no evidence of a statistically significant association between median survival and CA19-9 dosage (p=0.212), tumor location (p=0.482), first treatment performed (p=0.337), lymphovascular invasion (p=0.286), and age (p=0.152). However, the number of lines of chemotherapy was significantly associated with survival (log-rank p=0.013), with an estimated median survival of 10.2 months for patients who received up to two lines of treatment and 23.5 months for those receiving more than two lines of chemotherapy.

Conclusion

The survival of patients treated was longer than that reported in the literature. The only statistically significant factor related to increased survival was higher number of lines of chemotherapy received. We believe that the higher socioeconomic status of patients surveyed in this study, as well as their greater access to treatment options, may have influenced their overall survival.

Metastases of pancreatic adenocarcinoma: A systematic review of literature and a new functional concept

INTRODUCTION

Pancreatic cancer, especially Pancreatic Adenocarcinoma, is still associated with a high mortality and morbidity for affected patients notwithstanding considerable progresses in diagnosis and both surgical pharmacological therapy. Despite metastases from colorectal, gastric and neuroendocrine primary tumor and their treatment are widely reported, the literature has been rarely investigated the impact of localization and numbers of pancreatic metastases. This study performed a systematic analysis of the most recent scientific literature on the natural history of Pancreatic Adenocarcinoma focusing attention on the role that the "M" parameter has on a possible prognostic stratification of these patients.

MATERIAL AND METHODS

PubMed and Science Direct databases were searched for relevant articles on these issue.

RESULTS

Initial database searches yielded 7231 studies from PubMed and 29101 from Science Direct. We evaluated 1031 eligible full text articles.

CONCLUSIONS

An updated insight into the world of Pancreatic Tumors might help physicians in better evaluating mechanisms of metastases, patients selection and survival and in programming appropriate interventions to modify the worst outcomes of advanced disease.

Pharmacological inhibition and genetic knockdown of exchange protein directly activated by cAMP 1 reduce pancreatic cancer metastasis in vivo

cAMP plays a critical role in regulating migration of various cancers. This role is context dependent and is determined by which of the two main cAMP sensors is at play: cAMP-dependent protein kinase or exchange protein directly activated by cAMP (EPAC). Recently, we have shown that the cAMP sensor protein EPAC1 promotes invasion/migration of pancreatic ductal adenocarcinoma (PDA) in vitro. In this study, we investigated the role of EPAC1 in invasion and metastasis of PDA in vivo, and evaluated the therapeutic potential of EPAC inhibitors as antimetastasis agents for this neoplasm. We employed an orthotopic metastatic mouse model in which the PDA cells MIA PaCa-2 were injected into the pancreas of athymic nude mice, and their local and distant spread was monitored by in vivo imaging and histologic evaluation of the number of metastatic foci in the liver. Either genetic suppression of EPAC1 or its pharmacologic inhibition with 3-(5-tert-butyl-isoxazol-3-yl)-2-[(3-chloro-phenyl)-hydrazono]-3-oxo-propionitrile, an EPAC-specific antagonist recently identified in our laboratory, decreased invasion and metastasis of the PDA cells. Mechanistically, EPAC1 promotes activation and trafficking of integrin β1, which plays an essential role in PDA migration and metastasis. Our data show that EPAC1 facilitates metastasis of PDA cells and EPAC1 might be a potential novel therapeutic target for developing antimetastasis agents for PDA.